A five stroke method of ideographic character data entry exists and is widely used in China and other parts of the world. In this method, five basic strokes are mapped to five computer digit keys located on the right side of the keyboard. The method is cumbersome and slow to use as it requires a large number of strokes to be entered on average to define a Chinese character.
In a known keyboard method, ten basic Chinese character strokes are mapped to ten keys of a computer keyboard: W, E, R, U, I, O, D, F, J and K. Twelve frequently used Chinese character radicals are mapped to another twelve keys: Q, A, S, L, Z, X, C, V, B, N, M and P. This method also uses ten digit keys plus the "-" key to select the candidates.
In the latter method, when a user enters the first stroke of a Chinese character, the most possible eleven candidate Chinese characters with the same first stroke are displayed. If the user cannot find the Chinese character he wants to input, the user enters its second stroke. As a result of entering the second stroke, the most possible eleven candidate Chinese characters with the same first two strokes are displayed. This process continues until the user finds the Chinese character he wants to input. When the user finds the Chinese character that he wants to input, the user can select the Chinese character from a candidate list by using the ten digit keys plus the "-" key on the computer keyboard.
The above process is also applicable when the user wants to input a Chinese character by first entering its radical followed by subsequent strokes. This method has the drawback of requiring at least 33 keys for data entry, which is acceptable for a full size computer keyboard, but is too many keys for a compact data entry device such as a wired telephone, wireless telephone, pager, keypad or the like.
There exists a need for an apparatus that maps the thirty Chinese basic strokes and the ten frequently used radicals to an input pad with a smaller number of keys, and a method that solves the ambiguity problem caused by such a mapping. There also exists a need to alleviate a problem of requiring the user to entering many strokes of a desired character.